Means and methods for signal validation for sizing spherical objects

Methods and apparatuses for validating signals to determine sizes and velocities of spherical objects are described. Light is scattered from a spherical object to form an interference fringe pattern. Portions of the interference fringe pattern are received by photodetectors. In response, the photodetectors generate time varying electrical signals. At least one of the time varying signals is partitioned into timing segments. The timing segments are processed to determine one or more timing parameters. A timing parameter consistency between at least two of the timing segments is verified. At least one of the time varying signals is validated based on the timing parameter consistency. The time varying electrical signal is accepted if a timing parameter difference is less or equal to a predetermined timing parameter error threshold. The time varying electrical signal is rejected if the timing parameter difference is larger than the predetermined timing parameter error threshold.